Refrigerating system



G. HILGER 1,889,988

REFRIGERATING SYSTEM Dec. 6, 1932.

Filed Sept. 17, 1928 LUGnZFJf 660136 Hz) 67, A W aq Patented Dec. 6, 1932 UNITED STATES PATENT OFFICE REFRIGERATING SYSTEM Application filed September 17, 1928. Serial No. 306,563.

I he present invention relates to improvements in refrigerating systems, and particularly such systems in which a plurality of refrigerating units are connected to a central operating plant.

Refrigerating systems of this character are adapted to numerous applications, but are most commonly employed in apartment buildings wherein each apartment is provided with a refrigerating unit or box. The units usually are arranged in vertical stands.

In prior constructions, a substantial liquid head is created in each stand, this head being related to the height of the stand. As a result, a high feed pressure is required to force the refrigerant upwardly through the succe-isive units, and hence the height of the stand is limited, and the efficiency of refrigoration is relatively low. An uneven heat flow from the bottom to the top of the stand obtains the operation of the upper units often being unsatisfactory. Due to the difference in heat transfer, individual temperature controls for the units are required.

The primary objects of the invention, therefore. reside in the provision of a new and improved refrigerating system, having a plurality of units preferably arranged in a stand, in which the liquid head is substantially eliminated, which can operate on a relatively low pressure and low pressure differences, in which there is but a slight temperature difference between the units, said units having substantially the same evaporating effect, and in which an eXact control is unnecessary, one

control for each stand suflicing.

A more specific object resides in the provision of a novel refrigerating system comprising a plurality of units arranged in stands in which the refrigerant is carried from each unit to the next by an injector action.

Another object is to provide a new and improved system in which the gas superheated by the walls of each lower unit is desuperheated by the incoming feed, thereby increasing the evaporating effect of the next unit.

Further objects and advantages will become apparent as the description proceeds.

In the accompanying drawing, Fig. 1 is a perspective view of a refrigerating system embodying the features of my invention.

Fig. 2 is a sectional view of one of the units taken along line 2-2 of Fig. 1.

Fig. 3 is an elevational view of a modified form of the invention.

Fig. 4 is a fragmentary sectional view of the form shown in Fig. 3.

Fig. 5 is a fragmentary perspective view of the inlet end of one of the connecting feed ipes.

While the invention is susceptible of various modifications and alternative constructions,

I have shown in the drawing and will herein describe in detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Referring more particularly to the drawing, the exemplary embodiment of the invention comprises a plurality of refrigerating units arranged in stands or at different levels.

In the present instance, three units 1011 12, vertically alined in a single stand, are shown.

The units 10-11-12 may be of any suitable construction. Preferably, the units are alike in construction, each comprising a block 18 of suitable material, such as iron. Each block 13 is formed with inner and outer peripheral walls 1415 defining an intermediate space or chamber 16, and end walls 17-18 closing the ends of said chamber. The inner wall 14 defines a central space or compartment 19 opening longitudinally through the block 13. Suitable heat transferring vanes 20 and 21 are formed respectively in the sides of the walls 1415. In the present instance, the vanes 19 extend longitudinally and the vanes 20 extend transversely of the block 13.

Each of the units is provided with suitable inlet and outlet means. In the present instance, these means comprise an inlet spray pipe 22 and an outlet pipe 23. In each of the lower units, i. e.--the units 10 and 11, the spray pipe 22 is disposed horizontally in the chamher 16 just under the upper wall of the block 13, and the pipe 23 extends downwardly from the upper wall a substantial distance into the chamber, for example to the vertical center at one side of the compartment 19. In the top unit 12, the positions of the pipes 2223 are reversed. The inlet end of each of the lower pipes 23 is slotted longitudinally, six equally spaced slots 24 being provided in the present instance, as best shown in Fig. 5.

The units 101112 are connected in series to a central refrigerating plant (not shown) preferably of standard construction. A suitable plant is shown in my Patent No. 1,601,445, dated Sept. 28, 1926. The system may be operated on any suitable refrigerant, but for purposes of illustration let it be assumed that the refrigerant is ammonia. In the present instance, an ammonia feed line 25 from the plant is connected to the inlet spray pipe 22 of the unit 10. The outlet pipes 23 of the units 10 and 11 are connected respectively by feed pipes 26 and 27 to the inlet pipes 22 of the units 11 and 12. The outlet pipe 23 of the unit 12 is connected to a return line 28 leading to the plant.

While the invention in its broadest concept is not limited to the control means governing the supply of refrigerant, asingle control for each entire stand of units preferably is provided. This control may be of any suitable character, and in the present instance comprises a valve 29 in the feed line 25 responsive to the temperature of the fluid returning in the line 28. Also interposed in the feed line 25 at the inlet side of the valve 28 are a constant pressure reducing valve 30, preferably of standard construction. and a hand operable cut-off valve 31. Suitable constructions for the valves 29 and 30 are disclosed in the above-mentioned patent.

In operation, liquid ammonia at a predetermined pressure determined by the valve 30 is supplied to the spray pipe 22 of the unit 10. The amount of liquid supplied is automatically controlled through the medium of the valve 29 by the condition of the returning gas in the line'28. When starting, the liquid level in the unit 10 will not reach the inlet of the pipe 23, and hence ammonia vapor will pass freely on to the other units. However, the liquid level will rise until it reaches or slightly immerses the free inlet end of the pipe 22. At this time, the ammonia vapor, which is under pressure, will force its way through the slight amount of liquid tending to seal the end of the pipe 23 into line 26, and in so doing will carry along part of the liquid. This action is in the nature of an injector action, and serves to convey the liquid from one unit to another without having to act against a substantial liquid head. The slots 24 are proportional in area to the pressure, and serve to break up the entrained liquid to cause a finer atomized condition.

The vapor enters the pipe 23 through the slots 24 and also through the open end, and as the llquid level falls toward the end, the percentage of liquid entrained in the outgoing vapor increases. The liquid level will continue to fall until it is below the when the ammonia vapor again will pass freely on to the other units. Thereupon, the liquid again will commence to rise.- and the foregoing action will be repeated. Thus, the liquid level fluctuates slightly, and quantities of the liquid are lifted periodically from the unit 10 to the unit 11. The fluctuating level of the liquid from slightly below to slightly above the inlet end of the pipe 23 is referred to herein and in the claims as the normal level of the liquid. The injector action in any one unit is operable without regard to the relative positions of the units, which preferably are arranged in vertically spaced relation, and perse constitutes one of the broad features of the invention.

It will be noted that no opposing liquid .head is present, and that only a slight pressure difference between consecutive units is necessary to cause the foregoing action. The action in the unit 11 is the same as in the unit 10. In the unit 12, the ammonia vapor is withdrawn without entrained liquid into the return line 28. Obviously, the pressure dif ference between the feed and return lines, and the height of the liquid in the unit 12 are controlled by the valve 29. In view of the small pressure differences between the units 10 11-12, but small temperature differences exist. and hence the refrigerating effects of the units are substantially the same. Hence, an equal heat flow from bottom to top obtains.

In the units 10 and 11, the ammonia vapor tends to become superheated by contact with the walls of the blocks 13. The incoming liquid is sprayed into the ammonia vapor, and hence removes this superheat. As a result, only saturated ammonia vapor passes with or without liquid to the successive units, thereby maintaining a high evaporating effeet in the latter.

In the modified form of the invention, shown in Figs. 3 and 4, four refrigerating units 3233-3435 are provided. Each unit comprises a header 36 and a pipe coil 37 connected at its inlet and outlet ends respectively to the lower and upper ends of the header. Preferably, the header 36 comprises a hollow upright cylinder having end walls 38 and defining a closed chamber 39. The headers 36 are arranged in vertically superimposed position to form a' vertical stand. The lower header 36 is connected to the feed line 25, and the upper end of the upper header is connected to the return line 28.

Connecting the adjacent headers of the units 32-333435 are a plurality of tubes 404142. These tubes are open at both ends and project through the contacting or end of the pipe 23,

adjacent end walls 38. The upper or discharge end of each tube extends substantially above the lower or inlet end of the next tube.

The operation is substantially the same as in the form shown in Figs. 1 and 2. As the liquid level in each of the three lower units rises to or above the inlet end of the corresponding connecting tube, a mixture of vapor and liquid will be carried over into the next unit. When the liquid level falls below the inlet end of the tube, only ammonia vapor will pass through the tube. The vapor will be saturated. Obviously, the liquid in each unit will circulate through the coil 37. The vapor from the upper header is withdrawn through the return pi 28.

It will be evident t at I have provided an advantageous system comprising a plurality of units in which the refrigerant passes from each unit to the next by an injector action. The units are arranged at different levels, although the invention in its broadest concept is not limited to this arrangement. The construction is relatively simple and inexpensive. The system does not require a close and sensitive control for each unit, a single control for each stand of units being adequate. No substantial liquid head need be overcome, and hence but a slight pressure difference exists. As a result, the evaporating effect of the units is substantially the same.

I claim as my invention:

1. A refrigerating system comprising, in combination, a refrigerating unit having a space adapted to contain separated liquid and vapor phases of the refrigerant, inlet means for supplying refrigerant at a predetermined pressure, and outlet means for discharging refrigerant at a pressure lower than said predetermined pressure, said outlet means opening from said space at a substantial distance from the top, the liquid tending to rise to said outlet means, and the vapor entering said outlet means tending to entrain liquid when the level of the latter is at or above the inlet of said outlet means.

2. A refrigerating system, comprising, in combination, a refrigerating unit having a space adapted to contain separated liquid and vapor phases of the refrigerant, an inlet line for supplying refrigerant and opening to the normal vapor space in said unit, and a discharge line having its inlet end disposed at the normal level of the liquid, and having its discharge end opening to a lower pressure than normally exists in said space, the vapor tending to pass freely to said discharge line when the liquid is below the inlet of said d'scharge line, and to pass to said discharge line with entrained liquid when the liquid is at or above the inlet of said discharge line.

3. A refrigerating system comprising, in combination, a refrigerating unit having a space adapted to contain separated liquid and vapor phases of the refrigerant, an inlet line each havin for supplying refrigerant to said unit, said line having a spray discharge end disposed in the normal vapor space, and a discharge line having its inlet end disposed below said spray discharge end.

4. A refrigerating system comprising, in combination, a pair of refrigerating units,

a closed space adapted to contain a liquid in the bottom, and a vapor in the top, an inlet line opening to the top of the space in said first unit, and a connecting line having its inlet end opening at an intermediate point in the space in said first unit substantially below the discharge end of said inlet line, and for discharging vapor and liquid'to said second unit.

5. A refrigerating system comprising, in combination, a air of refrigerating units, each having a c osed space ada ted to contain a liquid in the bottom, an a vapor in the top, an inlet line opening to the top of the space in said first unit, a connecting vapor and liquid line having its inlet end opening downwardly into the space in said first unit at a point substantially below the discharge end of said inlet line, and having its discharge end opening to the top of the space in sald second unit, and a line opening from the s ace in said second unit at a point substa-ntlally below the discharge end of said connecting line, and means for automatically maintaining a progressive pressure drop from said inlet line to said last mentioned line.

6. A refrigerating system comprising, in combination, a pair of refrigerating units, each having a closed space ada ted to contain a liquid in the bottom, an a vapor in the top, an inlet line opening to the top of the space insaid first unit, a connecting vapor and liquid line having its inlet .end opening downwardly into the space in said first unit at a point substantially below the discharge end of said inlet line, and having its discharge end opening to the space in said second unit at a point substantially below the top of said space, and a gas take-ofi' line opening from the top of'said second unit.

7. A refrigerating system comprising, in combination, a refrigerating unit having a space adapted to contain separated liquid and vapor phases of the refrigerant, an inlet line for supplying refrigerant to said unit, said line having a spray discharge end disposed in the normal vapor space, a single discharge line from said space, said discharge line having its inlet end disposed below said spray discharge end, and means for maintaining a lower pressure in said discharge line than in said inlet line.

8. A refrigerating system comprising, in combination, a pair of vertically spaced refrigerating units, each having a closed space adapted to contain a liquid in the bottom, and a vapor in the top, an inlet line opening to the lower unit, a connecting vapor and. liquid line having its inletend opening at an intermediate point below the top in the space in said lower unit, and discharging to the upper unit, and means for maintaining a lower pressure in said upper unit than in said lower unit.

' 9. A refrigerating system comprising, in combination, a pair of. vertically spaced refrigerating units, each having a closed space adapted to contain a liquid in the bottom, and a vapor in the top, a feed line having a spray opening to the top of the s ace in said first unit, a connectin vapor an liquid line having its inlet end o ening downwardly into the space in said rst unit at a point substantially below said spray, and having a spray at its discharge end opening to the top of the space in said second unit, a line opening from the s ace in said second unit at a point substantially below the spray of said connecting line, and means for maintaining a decreasmgpressure gradient through said system.

10. A refrigeratin system comprising, in combination, a stan of three refrigerating units, each having a closed space adapted to contain a liquid in the bottom, and a vapor in the top, an inlet line opening to the top of the space in the first unit, a connecting line having its inlet end opening into the spahe in said first unit at a point substantially below the discharge end of said inlet line, and having its discharge end opening to the top of the space in the second unit, a connecting line having its inlet end opening into the f space in said second unit at a point substantially below the inlet of said first mentioned connecting line, and having its discharge end opening to a third unit, a line opening from the top of said third unit, and means for creating a pressure drop through said successive units.

11. A refrigerating systemcomprising, in combination, a plurality of superimposed units, including first, last and intermediate units, each having a hollow block and a coil opening from and to said block, means for supplying liquid refrigerant at a predetermined pressure to the first block, means for withdrawing vapor from said last block, means responsive to the temperature of the vapor from said last block for controlling the supply of refrigerant to said first block, connecting vapor and liquid pipes between said blocks, each pipe extending through the adjacent'walls of successive blocks, the outlet end of each pipe extending closely to the top of the block and the inlet end of each pipe extending below the outlet end of the preceding pipe.

12. A refrigerating system comprising, in combination, a refrigerating unit having a space adapted to contain separated liquid and vapor phases of the refrigerant, an Inlet 5 line for supplying refrigerant under pressure, a liquid and vapor outlet line having its end disposed at the normal level of the liquid and discharging to a pressure lower than the inlet pressure, and means formed on the inlet of said outlet line causing the level of the liquid to determine the proportion of liquid and vapor discharged.

13. A refrigerating system comprising, in combination, a pair of vertically spaced refrigerating units, the lower unit having a chamber adapted to contain separated liquid and vapor phases of the refrigerant, means for supplying refrigerant to. said lower unit, injector means utilizing the vapor in said lower unit as a driving fluid for elevating by entrainment liquid refrigerant from said chamber to the upper unit, and means for maintaining a lower pressure in said upper unit than in said lower unit.

14. A refrigerating system comprising, in

combination, a pair of vertically spaced refrigerating units, the lower unit having a chamber adapted to contain separated liquid and vapor phases of the refrigerant, means for supplying refrigerant to said lower unit, injector means utilizing the vapor in said lower unit as a driving fluid for elevating by entrainment liquid refrigerant from said chamber to the upper unit, means for maintaining a lower pressure in said upper unit than in said lower unit, and a circulating coil openin from said chamber. 7

15. A re rigerating system comprising, in combination, a pair of vertically spaced rerigerating units, the lower unit having a chamber adapted to contain separated liquid and vapor phases of the refrigerant, means for supplying refrigerant to said lower unit, injector means utilizing the vapor in said lower unit as a driving fluid for elevating by entrainment liquid refrigerant from said chamber to the upper unit, means for maintaining a lower pressure in said upper unit than in said lower unit, and two circulating coils one opening from and discharging to each of said refrigerating units.

16. A refrigerating system comprising, in combination, a vertical header having partition means defining a plurality of vertically. superimposed chambers, means for supplying liquid refrigerant to the bottom chamber, injector means for conveying vapor or vapor and entrained liquid refrigerant from each chamber except the uppermost chamber upwardly to an overhead chamber, and means for withdrawing vapor from the uppermost chamber.

17. A refrigerating system comprising, in combination, a vertical header having partition means defining a plurality of vertically superimposed chambers, means for supplying liquidrofrigerant to the bottom cham-' ber, m ectQr means for conveying vapor or vapor and entrained liquid refrlgerant from each chamber except the uppermost ch amber -ity of liquid circulating upwardly to an overhead chamber, a pluralcoils opening from and to said respective chambers, and means for withdrawing vapor from the uppermost chamber.

18. A refrigerating system comprising, in combination, a vertical stand of superimposed chambers, means for supplying liquid refrigerant to the lowermost chamber, injector means for conveying vapor or a mixture of vaporand entrained liquid upwardly from each chamber to the next chamber, means for circulating refrigerant from each of the chambers through a tortuous path, and means for withdrawing refrigerant from the uppermost chamber.

19. A refrigerating system comprising, in combination, a first refrigerating unit having a space adapted to contain separated liquid and vapor phases of the refrigerant, an inlet line for supplying refrigerant under pressure to said unit, a second refrigerating unit located at a higher elevation than said first unit, the pressure in said second unit being lower than in said first unit, and an outlet liquid and vapor line having its inlet end opening at the normal level of the liquid in said first unit to cause an injector action at the surface of the liquid, and discharging to said second unit.

20. A refrigerating system comprising, in

combination, a first refrigerating unit having a space adapted to contain separated liquid and vapor phases of the refrigerant, an inlet line for supplying refrigerant in excess of the refrigeration requirements of said unit, a second refrigerating unit, a single outlet line for discharging liquid and vapor opening from said space, the inlet of said outlet line opening substantially downwardly to said space at a. point below the top thereof, to cause an injector action at the surface of the liquid when the level of the liquid reaches said point and the discharge end of said outlet line opening to said second unit, and means for maintaining a lower pressure in said second unit than in said first unit.

21. A refrigerating system comprising, in combination, a hollow refrigerating block having a central recess opening therethrough with external-cooling ribs on the inner and outer peripheral surfaces and having a generally annular internal space adapted to contain separated liquid and vapor phases of the refrigerant, an inlet line for supplying refrigerant to the ing a spaceadapted to contain separated liquid and vapor phases of the refrigerant, a second refrigerating unit at a lower pressure than normally exists in said first unit, an inlet line for -supplying refrigerant to said space, and a liquid and vapor discharge line having its inlet end opening at the normal level of the liquid to cause an injector action at the surface of the liquid, and having its discharge end opening to said second unit, the inlet end of said discharge line being formed with a plurality of peripherally spaced longitudinal slots open at their outer ends to increase said injector action.

23. A refrigerating system comprising, in combination, two vertically spaced refrigerating units each having a hollow block with a space adapted to contain separated liquid and vapor phases of the refrigerant,

and having a circulating coil opening from and to said space, an inlet line for supplying lower space, a single liquid and 'vapor line discharging to the upper space and having its inlet end in said lower block opening below the top of said lower space to cause an injector action at the surface of the liquid when the level of the liquid reaches said inlet end, and means for maintaining alower pressure in said upper space than in saidlower space. i

In testimony whereof, I have hereunto affixed my signature.

GEORGE HILGER.

refrigerant at a. predetermined pressure to I said block, a refrigerating unit at a lower pressure than said predetermined pressure,

and an outlet line for liquid and vapor refrigerant opening downwardly at the normal level of the liquid in said space and discharging to said unit.

22. A refrigerating system, comprising, in combination, a first refrigerating unit hav- 

